The primary goal of the Animal Core is to provide accurate hemodynamic characterization of pulmonary vasoconstriction and vascular remodeling in relevant models of PH of projects 1-3. As described in the specific aims and tasks of the Animal Core, we will provide: (1) all the necessary support for the PH animal models that PPG investigators will utilize and monitor the hemodynamic progression of PH; (2) state of the art hemodynamic equipment and experts trained in all aspects of its use; and (3) Support PPG investigators in the process of animal euthanasia for tissue collection and organ harvest to insure the highest integrity of samples for molecular studies. The Animal Core is perfectly situated to support the mission of the PPG. It leverages fully equipped state of the art equipment and instrumentation to capture hemodynamic and heart function in a variety of animal species (mice, rats, calves etc.). This includes Millar and SciSense solid-state catheters, echocardiography, dye dilution methods and noninvasive monitoring of blood pressures (tail cuff; Harvard apparatus) and blood gases. The Animal Core leadership, Drs. Irwin and Stenmark, have a proven track record and national reputations for capturing hemodynamic signals in a variety of hypoxic animal models. The Animal Core staff are proven experts in: (1) animal catheter placements; (2) operating solid-state and fluid filled transducer systems;(3) evaluating echocardiography images; (4) animal handling and euthanasia and; (5) tissue and organ collection. Thus, we have the expertise to ensure the integrity of data collection from the actual inception of the animal study, during chronic hypoxic exposure and serial hemodynamic data acquisition ,and finally during tissue and organ harvest after animal euthanasia. The Animal Core will integrate, strengthen and synergize with the projects, and with the other Cores as well, thus providing the ability to significantly increase the overall human relevance of the findings of each project.